A013303 sec(log(x+1)-arctanh(x))=1+3/4!*x^4+90/6!*x^6+5145/8!*x^8...

1, 0, 3, 90, 5145, 472500, 63877275, 11947285350, 2955047720625, 934039255149000, 367306824871861875, 175873128591661751250, 100738594342264429175625, 68014527663768884135437500

Offset

0,3

Links

Table of n, a(n) for n=0..13.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sec[Log[x+1]-ArcTanh[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, May 15 2018 *)

Crossrefs

Sequence in context: A013304 A013298 A013302 * A166334 A209495 A168408

Adjacent sequences: A013300 A013301 A013302 * A013304 A013305 A013306

Keyword

nonn

Author

Patrick Demichel (patrick.demichel(AT)hp.com)

Status

approved